1. Field of the Invention
The present invention relates generally to a sound reproduction device, and more particularly to a sound reproduction device in which the enclosure for the speaker system is driven by the speaker system and thus forms an integral part of the speaker reproduction system.
2. Description of the Prior Art
Classically, sound reproduction systems have employed electromagnetic means which drive a diaphragm. The cone or dome shaped diaphragm and electromagnetic driver are usually housed in an inflexible enclosure but, in general, embedded in isolating material to physically insulate the speaker from the enclosure. Large openings are provided in the enclosure to permit air adjacent the opening to be excited by the speaker. Thus the conventional system of enclosure and speaker is highly directional in that only air in front of the enclosure opening is excited by the speaker.
Another approach is shown in U.S. Pat. No. 3,090,461. In this patent, a speaker is mounted in a vertical defined air column such that sound may emit from openings at the ends of the enclosure as well as through openings cut in the face of the enclosure. Except for the fact that this prior art enclosure utilizes open column of air, it is otherwise in many ways similar to the enclosure employed with string instruments. Again the enclosure is rigid and defines a volume of air which is excited. The resulting sound is directional as a function of the openings.
U.S. Pat. No. 3,486,578 discloses a somewhat similar arrangement wherein again openings are defined in at least one end of an enclosure as well as a elongated openings in the face of the enclosure.
Another interesting variation is discussed in U.S. Pat. No. 3,247,925. This disclosure, which relates to low frequency loud speaker systems, uses a signal stiff panel having, in one form, a honeycomb or foam interior sandwiched between steel sheets, to project sound when driven by another panel connected to a voice coil. The system, however, is rather specific as to frequency ranges, is limited as to direction, and requires rather critical relationships between the various panels.